If you have cast iron grates, follow these steps:

1. Wash the grates in the dishwasher.
2. Coat the grates with a thin layer of cooking oil.
3. Bake the grates in the oven on 350˚F for 10 minutes.

If you have porcelain-coated grates, simply place them in the dishwasher and coat any unfinished areas with a thin layer of cooking oil after washing.